Apparatus for vulcanizing flexible tubes



Nov. 23, 1948. H. MORRIS APPARATUS FOR VULCANIZING FLEXIBLE TUBES FiledSept. 21, 1945 4 Sheets-Shet 1 Gil a u A I a M- m 6, Q l 1 l I Fl W MI Fv I. a 1 i G, ,1 j k 1 n U0 V m I I 1 VII 1. AL M g n m A i W fl v. l uf w I, L W n a W fiv n J w L W 7 u 2 W n t I 6 A m 3 V M w m iPLI|FL|II|1I||| h l w 7 V 1 I A W I H f h f INVENTOR. HO WAR D LMORR IS. 9,.A. mm

H. I. MORRIS APPARATUS FOR VULCANIZING FLEXIBLE TUBES Noy. 23, 1948.

Filed Sept. 21, 1945 4 Sheets-Sheet 2 HOWARD LMORRIS. 9,u 0.(741i H. l.MORRIS APPARATUS FOR VULCANIZING FLEXIBLE TUBES Nov. 23, 1948.

4 Sheets-Sheet 4 Filed Sept. 21, 1945 FIG. 12

INVENTOR. HOWARD LMORRIS.

Y amina Patented Nov. 23, 1948 Howardl. Morria' San Marcos, Calif;assignor to The TYoder Company,

mention *of :Ohio

Cleveland, iOhio, a .cor-

Application September 21, 1945,'Serial No. 617307 1' Claim.

This invention relates "to apparatus f or repairingrubber products bytheapplication of heat thereto, more particularly products "of this type oftubular "shapein cross "section, the product shown for illustrativepurposes consisting or an inner tube for a'pneumatic tire. "However; itis notintendedthat the invention is to belimited to this kind oranarticle.

One object of the invention is to provide an improved vulcanizing:apparatus the parts of which are capable of ready assembly in relationto-thearea of the-product to be repaired and disassembly "relativethereto.

Another object of "the invention "is to provide an improved'apparatus ofthis character'capable of assembly around a portion of an annular shapedarticle of manufacture for heat'treating a portion thereof anddisassembly therefrom.

Another object *of the invention is to provide an improvedvulcanizingapparatus for repairing a tubular article formed of elasticmaterial, wherein the heat may be directly applied to therepair'material and wall of'the article.

Another object of the invention is to provide an improved apparatus'o'fthis type of relatively simple construction-arranged to permit readyassembly and disassembly thereof.

Another object of the invention is to provide an improved vulcanizingapparatusywherein during the-vulcanlzing operation, pressure is provided"for and maintained on the parts thereof by an air bag fOrm'edofmaterial other than rubber, whereby cost of operationis reduced and useof rubber is avoided.

Another object of the'invention is to provide an improved vulcaniz'ingapparatus capable of assembly around a' 'ilexi'ble tubeandemploying anirrflatatable member for exerting pressure, formed of inexpensivematerialpwhereby replacement may be made at minimum expense.

Another object or the invention is to provide an vflmproved vulcanizingapparatus capable "of assembly "around' a flexible tube and employing aninflatable :paper 'bag adapted to be wrapped around'theassembly forexerting pressure thereon when inflated, the paper "bag beingreplaceable at minimum expense, wherebythe cost of up-keep of theapparatus ismaterially reduced.

iOther objects of theinvention will'beapparent to'thoseskilled in theart'to which myinvention relates Ffrom the following description takenin connection with the accompanying drawings, wherein 1 .is:alongitudinal "section of an apparatus embodyingzmy invention, :01::the'line l"l of Fig.

" 2, ?shown in operativerelation'to an inner tube for a pneumatictireready'for vulcanizing the repair material'andtadjacentwall of thetube.

Fig. 2 is-a section :on the line 2-2 of Fig. 1;

Fig. 3 is "a side elevation of'the apparatus as shown'in Figs. '1"and*2,(looking in thedirection indicated by the line 3-3 of *Fig. 2) ,partsbeing broken "away;

Fig. .4 is a longitudinal section showing the position ofthe mandrel andcertain of the parts at one stage of the process in the assembly of theapparatus 'in operative relation to the inner tube;

Fig. Ea-is a perspective view of themandrel;

Fig. '6 is a'perspectiveyiew .of the inner shells for the heatingmember;

Fig"? isa-plan-view of a heating element;

Fig. 8 is a'perspective view-of the outer shells for the heated member;

'Fig. 9 is a perspective view of the binding-or pressure :member when infinal position around the" tube, the sections forming the heating memberand mandrel and :ready to be inflated (the tube and these latter partsbeing omitted to simplify the illustration) Fig. 10 is a fragmentarysection of the outer end portion of the pressure memberon the lineill-l0 of Fig. :9 (the valve being omitted).

Fig. 11 is a "perspective view of the sections forming the heatingmember'showing their connected relation when'assembled as shown in Figs.1, 2,-3and4.

Fig. 12 is -.a perspective view of one section of the heating member.

In the drawings, -l indicates as an entirety a mandrel preferably formedof heat resisting metal. The mandrelis formed in sections,preferablytwmsections 'la, It), to minimize the 'number 'of parts andthus facilitate assembly, "as shown in Figs. -1, 2, 4 :and .5 anddisassembly operations thereof. Corresponding end portions of the'mandrelsections la, ID, are enlarged'to provideacircumferentialshoulder lb for a-purpose later set "forth and an outer taperingwall lcterminating in a rounded end over which the walls of the tube A arepositioned as later set forth. 2 indicates as "an entirety aheatingmemher .(see Fig. 11) .preferably-comprisingtwo semicircularsections .29: adapted to be related sideedge to side-edge with the tube'therewithin. Each sectionZ-zr consists ofaninner shell 2a,.an outershell 4 andea heating element 3 therebetween (see Figs. 6, .7 andr8). Inthe assembly of these parts asheet of suitable insulating material la:'(suchas mica) isinterposed between the shel 2a. and the heating element3 and be tween the latter and the outer shell 4. The shells of eachsection are connected together (prefl erably tack welded) as shown at x.One side edge of each inner shell 2a is provided with spaced T-shapedlugs 2b, whereas its opposite side edge is formed with spaced recesses2b, which are complementary to the horizontal sec tions of the T-lugs217. Accordingly, in this arrangement, when the sections 251: areassembled, the lugs 21? of one inner shell 2a fit the recesses 2b of theother inner shell 2a. These complementary inter-related elements serveto guide the assembly of one section 23: on the other into sideby--siderelation against relative movement endwise and hold the two sectionstogether in locked relation. As shown, the vertical legs of the T-lugson one side edge of each inner shell 2a are of a length to extend equaldistances to either side of an imaginary diameter the radius of whichcorresponds to the radius of the adjacent shell, whereas its oppositeside edge is cut away on lines coincident with inner side edges 20 ofthe recesses 2b, so that when the sections 200 are assembled, cutawayside openings 20' are formed between the shells for a purpose later setforth. The opposite ends of the inner shells 2a are provided withflanges 2x, 2x", and when assembled on the mandrel I the flanges 2x abutthe shoulder lb on the latter. Between the flanges 2x" of each shell211, its wall is provided with an extension 211 (preferably disposedmidway its side edges), which is curvilinearly embossed inwardly toaccommodate the cable 3a for the current supply leads for the adjacentheating element 3. As will be observed, the flanges 2w, 2.1:", on eachinner shell 2a engage the opposite ends of the adjacent heating element3 and mica sheets lat. Each heating element 3 consists of a sheet ofsuitable insulating material 327, such as mica, and a resistance 31)wound or zigzag wrapped thereon. sheet has a length substantiallyco-extensive with the surface area of the adjacent shell 20., betweenits side edges and a width to flt between the flanges 202', 2r, thereof.The opposite end resistance 31) are reeved to maintain them out ofcontact and uniformly spaced. The cable 30. for the input and outputleads, which are connected to each resistance 3b, engages one end of themica sheets lac preferably midway their side edges. The resistanceextends in loop form through alternate notches 35c to the opposite sideedges of the mica sheet as shown at 30, 3c; the loops then extendthrough the remaining notches mica sheet 3?), as shown pleting thecircuit.

The outer shells 4 of the sections 2x are formed relatively high heatconducting metal. The inner ends of the shells 4, when the sections 2mare assembled, abut the shoulder I b of the mandrel i (see Fig. 1). Theouter end of each outer shell 4 is provided with inwardly extendingspaced lugs 4a which engage the adjacent extension 211. whereas itsopposite or inner end co-operates with the adjacent flange 23:" at theinner end of the adjacent inner shell 2a to enclose the adjacent heatingelement 3. The lugs shell are spaced to provide an opening for theadjacent cable 3a, (see Fig. 1). 42; indicates bars on the inner wall ofeach at 3.7:. thereby comother side edge of the outer shell 4,preferably formed integrally therewith and extending along the oppositeside edges of the shell, these bars being arranged to engagecorresponding bars on the side edges of the other outer shell when thesections c are assembled. As shown in Fig. 2 and 11, when the sections29s are assembled, the bars 4b extend into the openings 20 formedbetween the inner shells 2a. The bars 4?) on each outer shell areformed. with alined slots 40 through which the legs of the if-shapedlugs 2b of the inner shells 2a extend. As will be apparent, when theheating members 23: are assembled, the bars 4?] co-operate with theT-lugs 2b to lock them and. the sections of the mandrel l in assembledrelation.

Each of the cables 3a is clamped to one of the extensions Ed by a plate3', the opposite ends of which are secured to the adjacent extension inany desired manner, such as screws.

In carrying out my process the first step consists in assembling thesections 2a: of the heating member 2 around the tire tube A and lockingthem together through the co-action of the T-lugs 2b, recesses 2b andbars 4b; next, the two sections la, i'b, of the mandrel l are insertedwithin the heating member 2 around the tube A; next, the mandrel i andheating member 2 are positioned in spaced relation to the hole in thetube A (such spacing being approximately equal to half the length of themandrel i) and the patch 35 to be vulcanized is applied to the hole;next, the tube A is inflated until its diameter approximates the outsidediameter of the heating member 2 next, the tube walls are folded backover the tapered end lc of the mandrel and into surrounding relation tothe heating member 2, as shown at a, a" (see Fig. 4); next, the tube Ais deflated to reduce its diameter to approximately its normal diameter.

The next step of the process consists in. securing the folded portions11, a", under pressure in fixed relation to the heating member 2. Forthis purpose I employ an air bag (-2 and clamping means indicated as anentirety at 7. The air bag 6 consists of an elongated closed bag formedof suitable non-porous fabric but preferably non-porous paper capable ofholding air at a pressure of 40 to 60 lbs. when inflated. The bag 6 awidth approximating the length of the heating member 2, and a lengthsuflicient to be wrapped two or three times around the folded portions(1, a", of the tube A. Adjacent its outer end, the outer wall of the bag6 is formed with an opening 6' in which a suitable air valve is mounted.The valve may be similar in construction to the valves used in innertubes or an externally threaded tube 611 having a flange at its innerend engaging the inner surface of the outer wall of the bag, theexternal threads serving to take a nut 61) to clamp the bag wall betweenit and the flange and a threaded cap (not shown) to close the tube 6a.The opposite end portions of the bag 6 are sealed face-to-face to avoidany folding thereof, whereas the side portions of the material aresealed in overlapped portions 11', a, and its outer free end secured tothe adjacent 5a of adhesive clamping means formed of sheet metal la andclamping elements lb, 1c. The band 1a has a length somewhat greater thanthe circumference of the bag 6 when wrapped around the tube portions a,a", and a width substantially equal to that of the bag. The clampingelement lb consists of a fitting suitably fixed to the inner end of theband la and formed with a slot lb through which the outer end portion ofthe band is inserted. The clamping element 'lc consists of a pressureplate mounted on the inner end of two thumb screws 10' which arethreadedly mounted in the outer wall of the slot lb. The band la iswrapped snugly but not tightly around the bag 6 and its outer endportion clamped to the inner end of the band by the elements lb, 'lc.

Next, the bag is inflated with air to a pressure 4.0 lbs. or more, theeffect of which is to press the tube portions a, a", tightly anduniformly inwardly against the heating member 2 throughout itscircumference.

Finally, current is supplied to the resistances 3b to heat the heatingmember 2 for vulcanizing the tube for a period of time dependent uponthe thickness of the tube walls and curing speed of the material formingthe patch B.

I prefer to use a paper bag as a means of providing the necessarypressure in carrying out the vulcanizing operation as it eliminates theuse of a rubber tube and thereby avoids the utilization of rubber stock(either natural or synthetic) and paper bags being materially cheaperthan rubber tubes, the cost of the equipment and up-keep thereof isreduced since the paper bags can be readily replaced. For example, evenif each paper bag is used but once and discarded a new bag incurs butlittle expense. It will be observed that the lightness of the paper bagand its capability of being flattened (when deflated) and wrapped aroundthe heating element 2 and its outer end secured as shown in Fig. 9 whilethe clamping means 1 are being applied, greatly facilitates theoperation of positioning of the bag and the clampmg means.

To those skilled in the art to which my invention relates many changesin construction and widely differing embodiments and applications of theinvention will be apparent without departing from the spirit and scopethereof. My disclosures and the description herein are purelyillustrative and not intended to be in any sense limiting.

What I claim is:

In apparatus of the class described, the combination of a mandrel formedof curvilinear sections adapted to be applied to the walls of a flexibletube, a pair of semi-circular, separable members in engagement with saidmandrel, each of said members consisting of inner and outersemi-circular shells shaped to form a closed chamber therewithin, andmeans for connecting each end of one shell to the adjacent end of theother shell, separate means along the lateral sides of said members andwithin the outer surfaces of the outer shells for detachably connectingsaid members together, the outer surfaces of the outer shells forming awall over which portions of the tube are folded, an electricalresistance mounted in said chamber of that member related to thatportion of the tube to be treated, and having electrical terminalsleading through one end wall of said member for connection to a sourceof electrical current supply, whereby the adjacent member may be heated,an elongated inflatable member formed of non-porous, non-resilientflexible material convolutely wrapped around the folded over portions ofthe tube, non-extensible means surrounding and removably binding saidinflatable member while deflated in wrapped position, and a valvemounted in the outer end portion of said inflatable member adapted to beconnected with a source of fluid sup-ply under pressure, whereby saidinflatable member may be inflated to effect inward radial pressure onthe folded over portions of the tube against said heated member.

HOWARD I. MORRIS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,338,569 Hostler Apr. 2'1, 19201,364,362 Fetter Jan. 4, 1921 1,466,318 Waters Aug. 28, 1923 1,616,981Milligan Feb. 8, 1927 1,655,095 Fetter Jan. 3, 1928 1,707,794 BlakerApr. 2, 1929

